whiterose

linux unikernel
Log | Files | Refs | README | LICENSE | git clone https://git.ne02ptzero.me/git/whiterose

commit 5f739e4a491ab63730ef3b7464171340c689fbff
parent a667cb7a94d48a483fb5d6006fe04a440f1a42ce
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Tue, 12 Mar 2019 13:27:20 -0700

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "Assorted fixes (really no common topic here)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Make __vfs_write() static
  vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1
  pipe: stop using ->can_merge
  splice: don't merge into linked buffers
  fs: move generic stat response attr handling to vfs_getattr_nosec
  orangefs: don't reinitialize result_mask in ->getattr
  fs/devpts: always delete dcache dentry-s in dput()

Diffstat:
Mfs/devpts/inode.c | 1+
Mfs/orangefs/inode.c | 7++-----
Mfs/pipe.c | 32+++++++++++++++++++++++++++++---
Mfs/read_write.c | 10++++++++--
Mfs/splice.c | 8++++----
Mfs/stat.c | 12+++++++-----
Minclude/linux/pipe_fs_i.h | 8+-------
Mkernel/relay.c | 1-
Mkernel/trace/trace.c | 2--
Mnet/smc/smc_rx.c | 1-
10 files changed, 52 insertions(+), 30 deletions(-)

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c @@ -455,6 +455,7 @@ devpts_fill_super(struct super_block *s, void *data, int silent) s->s_blocksize_bits = 10; s->s_magic = DEVPTS_SUPER_MAGIC; s->s_op = &devpts_sops; + s->s_d_op = &simple_dentry_operations; s->s_time_gran = 1; error = -ENOMEM; diff --git a/fs/orangefs/inode.c b/fs/orangefs/inode.c @@ -261,11 +261,8 @@ int orangefs_getattr(const struct path *path, struct kstat *stat, generic_fillattr(inode, stat); /* override block size reported to stat */ - if (request_mask & STATX_SIZE) - stat->result_mask = STATX_BASIC_STATS; - else - stat->result_mask = STATX_BASIC_STATS & - ~STATX_SIZE; + if (!(request_mask & STATX_SIZE)) + stat->result_mask &= ~STATX_SIZE; stat->attributes_mask = STATX_ATTR_IMMUTABLE | STATX_ATTR_APPEND; diff --git a/fs/pipe.c b/fs/pipe.c @@ -225,8 +225,15 @@ void generic_pipe_buf_release(struct pipe_inode_info *pipe, } EXPORT_SYMBOL(generic_pipe_buf_release); +/* New data written to a pipe may be appended to a buffer with this type. */ static const struct pipe_buf_operations anon_pipe_buf_ops = { - .can_merge = 1, + .confirm = generic_pipe_buf_confirm, + .release = anon_pipe_buf_release, + .steal = anon_pipe_buf_steal, + .get = generic_pipe_buf_get, +}; + +static const struct pipe_buf_operations anon_pipe_buf_nomerge_ops = { .confirm = generic_pipe_buf_confirm, .release = anon_pipe_buf_release, .steal = anon_pipe_buf_steal, @@ -234,13 +241,32 @@ static const struct pipe_buf_operations anon_pipe_buf_ops = { }; static const struct pipe_buf_operations packet_pipe_buf_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = anon_pipe_buf_release, .steal = anon_pipe_buf_steal, .get = generic_pipe_buf_get, }; +/** + * pipe_buf_mark_unmergeable - mark a &struct pipe_buffer as unmergeable + * @buf: the buffer to mark + * + * Description: + * This function ensures that no future writes will be merged into the + * given &struct pipe_buffer. This is necessary when multiple pipe buffers + * share the same backing page. + */ +void pipe_buf_mark_unmergeable(struct pipe_buffer *buf) +{ + if (buf->ops == &anon_pipe_buf_ops) + buf->ops = &anon_pipe_buf_nomerge_ops; +} + +static bool pipe_buf_can_merge(struct pipe_buffer *buf) +{ + return buf->ops == &anon_pipe_buf_ops; +} + static ssize_t pipe_read(struct kiocb *iocb, struct iov_iter *to) { @@ -378,7 +404,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) struct pipe_buffer *buf = pipe->bufs + lastbuf; int offset = buf->offset + buf->len; - if (buf->ops->can_merge && offset + chars <= PAGE_SIZE) { + if (pipe_buf_can_merge(buf) && offset + chars <= PAGE_SIZE) { ret = pipe_buf_confirm(pipe, buf); if (ret) goto out; diff --git a/fs/read_write.c b/fs/read_write.c @@ -478,8 +478,8 @@ static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t return ret; } -ssize_t __vfs_write(struct file *file, const char __user *p, size_t count, - loff_t *pos) +static ssize_t __vfs_write(struct file *file, const char __user *p, + size_t count, loff_t *pos) { if (file->f_op->write) return file->f_op->write(file, p, count, pos); @@ -1238,6 +1238,9 @@ COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd, const struct compat_iovec __user *,vec, unsigned long, vlen, loff_t, pos, rwf_t, flags) { + if (pos == -1) + return do_compat_readv(fd, vec, vlen, flags); + return do_compat_preadv64(fd, vec, vlen, pos, flags); } #endif @@ -1344,6 +1347,9 @@ COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd, const struct compat_iovec __user *,vec, unsigned long, vlen, loff_t, pos, rwf_t, flags) { + if (pos == -1) + return do_compat_writev(fd, vec, vlen, flags); + return do_compat_pwritev64(fd, vec, vlen, pos, flags); } #endif diff --git a/fs/splice.c b/fs/splice.c @@ -138,7 +138,6 @@ error: } const struct pipe_buf_operations page_cache_pipe_buf_ops = { - .can_merge = 0, .confirm = page_cache_pipe_buf_confirm, .release = page_cache_pipe_buf_release, .steal = page_cache_pipe_buf_steal, @@ -156,7 +155,6 @@ static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, } static const struct pipe_buf_operations user_page_pipe_buf_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = page_cache_pipe_buf_release, .steal = user_page_pipe_buf_steal, @@ -326,7 +324,6 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, EXPORT_SYMBOL(generic_file_splice_read); const struct pipe_buf_operations default_pipe_buf_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = generic_pipe_buf_release, .steal = generic_pipe_buf_steal, @@ -341,7 +338,6 @@ static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe, /* Pipe buffer operations for a socket and similar. */ const struct pipe_buf_operations nosteal_pipe_buf_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = generic_pipe_buf_release, .steal = generic_pipe_buf_nosteal, @@ -1606,6 +1602,8 @@ retry: */ obuf->flags &= ~PIPE_BUF_FLAG_GIFT; + pipe_buf_mark_unmergeable(obuf); + obuf->len = len; opipe->nrbufs++; ibuf->offset += obuf->len; @@ -1680,6 +1678,8 @@ static int link_pipe(struct pipe_inode_info *ipipe, */ obuf->flags &= ~PIPE_BUF_FLAG_GIFT; + pipe_buf_mark_unmergeable(obuf); + if (obuf->len > len) obuf->len = len; diff --git a/fs/stat.c b/fs/stat.c @@ -45,11 +45,6 @@ void generic_fillattr(struct inode *inode, struct kstat *stat) stat->ctime = inode->i_ctime; stat->blksize = i_blocksize(inode); stat->blocks = inode->i_blocks; - - if (IS_NOATIME(inode)) - stat->result_mask &= ~STATX_ATIME; - if (IS_AUTOMOUNT(inode)) - stat->attributes |= STATX_ATTR_AUTOMOUNT; } EXPORT_SYMBOL(generic_fillattr); @@ -75,6 +70,13 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat, stat->result_mask |= STATX_BASIC_STATS; request_mask &= STATX_ALL; query_flags &= KSTAT_QUERY_FLAGS; + + /* allow the fs to override these if it really wants to */ + if (IS_NOATIME(inode)) + stat->result_mask &= ~STATX_ATIME; + if (IS_AUTOMOUNT(inode)) + stat->attributes |= STATX_ATTR_AUTOMOUNT; + if (inode->i_op->getattr) return inode->i_op->getattr(path, stat, request_mask, query_flags); diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h @@ -74,13 +74,6 @@ struct pipe_inode_info { */ struct pipe_buf_operations { /* - * This is set to 1, if the generic pipe read/write may coalesce - * data into an existing buffer. If this is set to 0, a new pipe - * page segment is always used for new data. - */ - int can_merge; - - /* * ->confirm() verifies that the data in the pipe buffer is there * and that the contents are good. If the pages in the pipe belong * to a file system, we may need to wait for IO completion in this @@ -182,6 +175,7 @@ void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *); int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *); +void pipe_buf_mark_unmergeable(struct pipe_buffer *buf); extern const struct pipe_buf_operations nosteal_pipe_buf_ops; diff --git a/kernel/relay.c b/kernel/relay.c @@ -1177,7 +1177,6 @@ static void relay_pipe_buf_release(struct pipe_inode_info *pipe, } static const struct pipe_buf_operations relay_pipe_buf_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = relay_pipe_buf_release, .steal = generic_pipe_buf_steal, diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c @@ -6023,7 +6023,6 @@ static void tracing_spd_release_pipe(struct splice_pipe_desc *spd, } static const struct pipe_buf_operations tracing_pipe_buf_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = generic_pipe_buf_release, .steal = generic_pipe_buf_steal, @@ -7050,7 +7049,6 @@ static void buffer_pipe_buf_get(struct pipe_inode_info *pipe, /* Pipe buffer operations for a buffer. */ static const struct pipe_buf_operations buffer_pipe_buf_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = buffer_pipe_buf_release, .steal = generic_pipe_buf_steal, diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c @@ -136,7 +136,6 @@ static int smc_rx_pipe_buf_nosteal(struct pipe_inode_info *pipe, } static const struct pipe_buf_operations smc_pipe_ops = { - .can_merge = 0, .confirm = generic_pipe_buf_confirm, .release = smc_rx_pipe_buf_release, .steal = smc_rx_pipe_buf_nosteal,